That's how devs in Patreon get their money. Logically speaking, it would be far cheaper to purchase a polished AAA game than to subscribe to these wannabe game devs on Patreon. Usually, by the time a game (support via Patreon) is completed, you would have paid the cost of perhaps 1 (minimum) or more AAA games.
The wannabe devs either tend to purposefully drag the development out to milk more money out of a single project with a slew of sordid excuses, or are really just doing it as a side hustle (which delays development too). Patreon games usually take 1-2 years to complete, and would cost around 3-5 bucks (lowpoint; there are some which minimum costs more than that) per month. That's around 36-60 bucks for the entire game in a year of subscription that may or may not see completion (at the mercy of the dev's discretion).